Articles 34–37

Articles 34–37 form the core of Part III, Section 4 of the Vienna Convention on the Law of Treaties (VCLT), 1969, codifying the ancient maxim pacta tertiis nec nocent nec prosunt — a treaty neither harms nor benefits third parties. A "third State" is defined in Article 2(1)(h) as a State not party to the treaty. Article 34 lays down the foundational rule: a treaty does not create either obligations or rights for a third State without its consent. The succeeding three articles articulate the precise exceptions and mechanics by which consent operates, distinguishing carefully between burdens and benefits.

Article 35 addresses obligations: a provision binds a third State only if the parties intend it to be the means of establishing the obligation and the third State expressly accepts that obligation in writing. The written-acceptance requirement makes the imposition of duties on non-parties deliberately exacting. Article 36, by contrast, treats rights more permissively: a right may arise for a third State if the parties so intend and the third State assents, with assent presumed so long as the contrary is not indicated, unless the treaty provides otherwise; the third State must comply with conditions for exercising that right. Article 37 governs revocation or modification — an Article 35 obligation may be revoked only with the consent of both the parties and the third State, whereas an Article 36 right may not be revoked or modified if it was intended to be non-revocable without the third State's consent. Article 38 (the immediate sequel) preserves the rule that nothing prevents a treaty norm from binding third States as customary international law.

Classic illustrations predate the VCLT but anchor the principles. The Permanent Court of International Justice in the Free Zones of Upper Savoy and the District of Gex case (France v. Switzerland, 1932) recognized that a stipulation in favour of a third State (Switzerland, under the 1815 settlement) could be enforceable. Treaties establishing "objective regimes" — the demilitarization of the Åland Islands, free navigation of the Suez Canal under the 1888 Constantinople Convention, and the Antarctic Treaty (1959) — illustrate arrangements asserting erga omnes effect, though the International Law Commission ultimately declined to codify "objective regimes" as a distinct category, leaving them to operate through consent or custom. As of 2026 the VCLT framework remains the governing reference, binding on its 116-plus parties and reflecting customary law for non-parties such as India and the United States.

For the international-law paper, Articles 34–37 are tested as the doctrinal statement of pacta tertiis and its exceptions. Expected question angles include: distinguishing the written acceptance required for obligations (Article 35) from the presumed assent for rights (Article 36); the revocation rules under Article 37; and the saving clause for customary law (Article 38) which explains how treaty provisions like UN Charter Article 2(6) reach non-members. Candidates should be ready to cite the Free Zones case and contrast the strict consent threshold for burdens against the liberal presumption for benefits, and to discuss whether "objective regimes" survive as an independent basis for third-party effect.